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(Model.)

' J.V A. DEMBRS, BURGLAR` ALARM.

Patented Mam 18, 1884.

:Eilev n l CJi Unirse STATES Pnrnnr -rrrcao BURGLAR-ALARM.

SPIFIATION forming part of Letters 'Patent No. 295,366, @ma Mai-@i1 is, 1884.

Application illcd October 18, 1883. (Model.)

To LEZ whom t may concern.-

Be it known that I, J. Acri-inn. Dnirnns, a citizen of the United States of America, residing at Great Falls, in the county of Stafford and State of New Hampshire, have invented certain new and useful Improvements in Alarms for Doors; and I do hereby declare the following to be a full, clear, and eX.- act description ci" the invention, such as will enable others skilled in the art to which it appertains to malte and use the same, reference being had to the accompanying drawings, andto letters or figures of reference marked thereon, which form a part of this specification.

This invention relates to certain new and useful improvements in alarms for doors, its object being to Lprovide a means which can be readily att-ached to and detached from adoor, and which will sound an alarm when the door iopened, said alarm being set when the door is closed; and my invention consists in an alarm which is incased within a box, which is provided with a spring-actuating means, which actuating means is wound or set by a lever attached to a dog, which lever comes in contact with the door-jamb when the door is closed, as wili be hereinafter more fully set forth, and is illustrated in the accompanying drawings, in which- Figure l is a perspective view, showing my improved attachment secu red to a door. Fig. 2 is a. vertical longitudinal section; and Fig. 3 is a front view, the case being shown in sections.

In the accompanying drawings, A represents a suitable box or case, which is provided with side pieces, a a, having hooks at their end, or other equivaient means, for attaching the same to a doorin a manner so that the box may be readiiy detached from the same. This box is provided at its upper end with a slot, b, through which passes an arm, B, which abnts against the door-jamb when the door is closed, as will be hereinafter set forth. Nithin the box is secured a suitable spring mechanism, C, which is provided with a train of gearing and escapement, the shaft of which escapement is provided with a hammer,

sound an alarm.

The construction of the spring mechanism and hammer-actuating means is of the usual form, and is fully illustrated in the accompanying drawings.

To the shaft D, upon which is secured the actuating-spring, is attached a dog, E, said shaftD being located below the slot o, so that when the door is closed, as shown in Fie. 2, said dog will be in an inclined position, and the arm B will rest upon the lower portion ofthe slot b, so as to be in a horizontal position.

At a suitable point within the box I provide a crank-shaft, F, which is located above the bell-hammer c, by means of which, when the alarm is attached to a door, the crankshaft can be turned, so as to bear upon the bell-hammer and render the same inoperative when it is desired not to sound an alarm.

Theoperation of myinvention is as follows: W'hen the box inelosing the alarm mechanism vis attached to a door and the brake or crankshaft F unset, the arm I5 will be thrown outward by the dog attached to the shaft which carries the mainspring1 and when the door is closed the arm will strike aoainst the jamb of the door and be pressed inwardly, and said arm will carry with it the dog E, so as to wind the spring; and as soon as the door is opened the spring, being free to act,will set the gearing in motion and sound an alarm.

Having thus described my invention, so that the same can be fully understood and made by those skilled in the art, I do not wish to limit myself to the precise construction herein shown, but reserve the right to modify or change the same within the scope and spirit of my invention; and

"What I claim as new, and desire to secure by Letters Patent, is-

l. In an alarm for doors, a case provided with hooks, whereby it maybe attached to a door, and provided with an alarm and springactuating means, said spring-actuating means being provided with a dog and arm, whereby c, which strikes against thc bell C', so as to L the spring` is Wound up when the arm is combined substantially as shown, and for the forced Within the receptacle, substantially as purpose set forth. 1o shown, and for the purpose set forth. In testimony whereof I affix my signaturein 2. In combination with the case A, having` presence of two witnesses. 5 an opening or slot, b, and inclosing an alarml J. ARTHUR DEMERS.

sounding mechanism7 the dog E, attached to I IVitnesses:

the shaft of the spring7 and provided at its end l WM. R. BURLEIGH, with an arm B, the parts being' organized a'nd IV. F. RUSSELL. 

